Questions and answers for exam Preparation

MCQs

Total Questions : 114 | Page 7 of 12 pages

Question 61. The cellular productivity in a continuous stirred tank fermenter (CSTF) increases with an increase in the dilution rate and reaches a maximum value. If the dilution rate is increased beyond the maximum point, the productivity will

decrease abruptly
increase
increase drastically
be zero

Discuss Question

Answer: Option A. -> decrease abruptly
Answer: (a).decrease abruptly

Question 62. Toxins accumulated in a reactor can lead to low biomass yields probably due to which of the following?

NAD+ is diverted away from homeostasis to anabolism
ATP is diverted away from homeostasis to anabolism
NAD+ is diverted away from anabolism to homeostasis
ATP is diverted away from anabolism to homeostasis

Discuss Question

Answer: Option D. -> ATP is diverted away from anabolism to homeostasis
Answer: (d).ATP is diverted away from anabolism to homeostasis

Question 63. Fluidized bed bioreactors provide higher mass transfer rates than packed bed bioreactors because

mixing is higher in fluidized bed bioreactors
particles move with the fluid in a fluidized bed bioreactor
immobilized particles are smaller in the fluidized bed bioreactors
all of the above

Discuss Question

Answer: Option B. -> particles move with the fluid in a fluidized bed bioreactor
Answer: (b).particles move with the fluid in a fluidized bed bioreactor

Question 64. In fed-batch fermentation, mass of substrate utilized is calculated using the relationship

initial mass of substrate in the reactor + final mass of substrate in the reactor + flow rate x [substrate in the feed]
initial mass of substrate in the reactor - final mass of substrate in the reactor + flow rate x [substrate in the feed]
initial mass of substrate in the reactor + final mass of substrate in the reactor - flow rate x [substrate in the feed]
initial mass of substrate in the reactor + final mass of substrate in the reactor - flow rate

Discuss Question

Answer: Option B. -> initial mass of substrate in the reactor - final mass of substrate in the reactor + flow rate x [substrate in the feed]
Answer: (b).initial mass of substrate in the reactor - final mass of substrate in the reactor + flow rate x [substrate in the feed]

Question 65. A chemostat has a liquid volume of 2 litres and is being fed at a rate of 4 litres per hour. Dilution rate for this reactor will be

2 litres
2 litres per hour
2 h¹
4 litres per hour

Discuss Question

Answer: Option C. -> 2 h¹
Answer: (c).2 h¹

Question 66. A culture system with constant environmental conditions maintained through continual provision of nutrient and removal of wastes is called __________ culture system.

continuous
batch
fed-batch
semi continuous

Discuss Question

Answer: Option A. -> continuous
Answer: (a).continuous

Question 67. A continuous reactor at steady state contains 0.04 g.l¹ of biomass and 0.02 g.l¹ of phenol. The feed contained 0.1 g.l¹ of phenol. The biomass yield would be

0.4 g.g¹
0.5 g.g¹
1.0 g.g¹
5.0 g.g¹

Discuss Question

Answer: Option B. -> 0.5 g.g¹
Answer: (b).0.5 g.g¹

Question 68. The growth of an organism on glucose is described by the following Monod model parameters: μm = 0.5 h¹ and Ks =0.1 g.l¹, if the concentration of glucose in the feed is 10 g.l¹ and the dilution rate is set to 0.4 h¹, then the steady state concentration of glucose in the effluent will be